Climate-related disasters, including hydrometeorological disasters, have increased over the last decade, accounting for more than 90% of all-natural disasters in Indonesia. To reduce the risk of disaster, the hydrometeorological disaster must be mitigated. The research, carried out at Sukakerti and Tugumukti villages in West Java, aimed at assessing flash flood disaster conditions and designing hydrometeorological disaster early warning instrumentation for community preparedness. Sukakerti Village has a V-shaped river valley and winding primary and secondary forest morphology. Rainfall-caused landslides precede flash floods. Tugumukti village is characterized by undulating hills and is situated directly on a small river flowing from Mount Burangrang. The river that caused the flash flood is only a few tens of meters wide, but settlements have sprung up all around it. Drought affects agricultural activities during the dry season. Hydrometeorological early warning instrumentation for landslides, flash floods, and agricultural droughts comprises radio communication between field devices and routers and a remote data center. Humidity, temperature, solar radiation, wind speed and direction, rainfall, soil moisture, slope, and ground vibration are all sensors. A speaker on the router warns the public of a potential disaster. This technology outperforms GSM and satellite communications in terms of cost, operation, and maintenance.